Wireless sensor networks provide an effective way of gathering data and also open up new sensing opportunities. Wireless sensor networks can be more useful if the data can be effectively retrieved from the sensor network. However, such networks typically operate in the Wi-Fi bands and are subject to interference.
Wi-Fi interference is a common and troublesome issue. The lack of wires that makes WLAN so attractive is also the feature that makes other consumer devices capable of causing Wi-Fi interference. Because the air is shared by all transmitters, transmissions by any device at the same frequency as an access point's (AP) radio can cause interference. Because 802.11 wireless networks operate in unlicensed bands used by many technologies, such as microwave ovens, video surveillance cameras, cordless phones, they are subject to interference. In addition, wireless access points sharing the same channel might interfere with each other. The effect of interference is highly dependent on the strength of the transmission and the distance from the interferer. Access points closest to and on the same channel as an interferer are affected more than those that are further away. Co-channel interference or adjacent channel interference can result from setting radios to bands that have overlapping channels. The channels might not all be in use by a network—neighboring signals can also cause interference.
While various coexistence techniques are known for mitigating the negative effects of such interference (see commonly assigned U.S. patent application Ser. No. 14/089,680, filed Nov. 25, 2013, entitled Channel Steering for Implementing Coexistence of Multiple Homogeneous Radios), running a physical coexistence bus is not always possible.
It would be desirable to provide techniques that increase wireless network bandwidth, reduce wireless network interference, and reduce sensor power consumption.